Hubbry Logo
Rocking stoneRocking stoneMain
Open search
Rocking stone
Community hub
Rocking stone
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Rocking stone
Rocking stone
from Wikipedia

Rocking Stone Viklan, Jelení stráň, Jizera Mountains

Rocking stones (also known as logan stones or logans) are large stones that are so finely balanced that the application of just a small force causes them to rock. Typically, rocking stones are residual corestones formed initially by spheroidal weathering and have later been exposed by erosion or glacial erratics left by retreating glaciers.[1][2] Natural rocking stones are found throughout the world.[2] A few rocking stones might be man-made megaliths.[citation needed]

Name

[edit]
The Logan Stone on the Rhinns of Kells in Galloway in 1789

The word "logan" is probably derived from the word "log", which in the Cornish dialect of English means to rock. In some parts of the United Kingdom, rocking stones or logan stones are called logging stones. The word "log" might be connected with the Danish word logre, which means to "wag a tail".

Davies Gilbert suggested that the word "logan" comes from a Cornish expression for the movement that someone makes when inebriated:

"It may be observed that I have always used the words Loging Rock for the celebrated stone at Trereen Dinas. Much learned research seems to have been idly expended on the supposed name, "Logan Rock." To log is a verb in general use throughout Cornwall for vibrating or rolling like a drunken man, and is frequently heard in provincial pronunciation for tug, characteristic of the modem present participle. The Loging Rock is, therefore, strictly descriptive of its peculiar motion."[3]

Examples of rocking stones

[edit]
Pedra dos Cadris, a rocking stone in Muxía

Such stones are common in Britain and other places around the world. For example, in Galicia, rocking stones are called pedras de abalar; some examples of these are along the Costa da Morte, particularly around Muxía; they include the Pedras de Barca.[4][5]

Pliny the Elder (23–79) wrote about a rock near Harpasa (in Caria, Asia Minor) "that can be moved with one finger, but that also resists a push made with the whole body."[6] Ptolemy (circa 90–168) wrote about the Gygonian rock, which he wrote "can only be moved with an asphodel and remains immovable by force."[7]

There are stones in Iona called na clachan-bràth, within the precincts of a burial ground, and placed on the pedestal of a cross, and have been according to Pennant, the supports of a tomb.[citation needed]

The Witch's Rocking Stone or Boarstone on the Craig o'Kyle in East Ayrshire

A massive 90 to 95 ton glacial erratic boulder near Halifax, Nova Scotia, can still be rocked with a lever, but used to move quite easily, before a band of sailors from the nearby Halifax garrison rocked it into a more stable configuration in the 1890s, and before its base was worn down by excessive rocking in the 1980s and '90s when a park was developed around it at Kidston Lake, in the Spryfield area of the municipality.[citation needed] It used to be a popular picnic destination; in Victorian times, people would travel from Halifax, climb upon it and spread their lunches, while enjoying the sensation of rocking gently while seated upon the huge rock.[citation needed]

The Pontypridd Rocking Stone in Wales is set within the middle of a Druidic stone circle.

Bosistow Logan Rock is at the head of Pendower Cove (sometimes written as Pendour Cove) near Zennor, Cornwall. It apparently was discovered by an employee of the lord of the local manor whose duty it was to watch the coast. A ship had been wrecked in the cove, and while watching ensuing activity, the employee leaned against a boulder. Suddenly, a gust of wind occurred, and the boulder shifted, or "logged". The longest side of this mass of stone is about 15 feet (4.6 m), and the circumference of its biggest end is about 20 feet (6.1 m). It is thought to weigh about 20 tons.[citation needed]

The Coylton or Witch's rocking stone in 1863

A rocking stone is recorded near the site of Saint Bride's Chapel. The Witch's or Boarstone stands on top of the Craigs of Kyle near Coylton in Ayrshire. It weighs around 30 tons and rests upon two or three stones. A large standing stone known as Wallace's stone is recorded to have stood nearby.[8]

A rocking stone is found near Loch Riecawr in South Ayrshire.[9]

In the parish of North Carrick in the Straiton District in South Ayrshire, about a quarter of a mile to the west of the White Laise, and near the March Dyke, a rocking stone named the Logan Stone exists. The Logan Stone is a grey granite rock and rests on greywacke, and can easily be moved with one hand. It is 4 feet 3 inches (1.30 m) by 4 feet (1.2 m), by 3 feet (0.91 m) high.[10]

Rinkusteinar in Oyndarfjørður, Eysturoy, Faroe Islands. The chain is connected to the mainland to make it easier to see the rock's movements.

There is a famous pair of rocking stones on the Faroese island of Eysturoy in the village of Oyndarfjørður. These are known as the Rinkusteinar. Local legend states that an old sorceress cursed two pirate ships that were menacing the village, turning them to stone. A chain connected to the mainland makes it easier to see the rock's movements.[11]

The Lugar rocking stone

Near Lugar in the Parish of Auchinleck in Ayrshire, Scotland, is the Lamargle or Lamargee rocking stone in a hollow by the Bello or Bellow Water near its junction with the Glenmore Water from which point the name Lugar Water is applied. It is made of two vertical stones, and a horizontal stone about 6 ft long, 3 ft broad, and 4 ft high. It was regarded as a Druidic monument or the grave of a Caledonian hero.[12] This stone has often been overlooked, as the OS maps give the wrong location; it sits beside the Bellow Water above its confluence with the Glenmore Water and not on Lamargle Hill.

The Kyaiktiyo Pagoda in Burma is a religious shrine built on top of a huge granite boulder that is also a rocking stone.[citation needed]

Some masses shaped by humans also exhibit similar behaviour (sometimes unintentionally). For example, in the ruins of the Roman temples at Jerash in Jordan (the "city of 1000 pillars"), some massive pillars move back and forth in the slightest breeze.[13]

Stones that used to move

[edit]

A stone used to rock on a gritstone outcrop on Warley Moor near Halifax in West Yorkshire. It had already ceased to rock when described by John Watson in 1775.[14]

The Rocking Stone at Cuff Hill in Ayrshire

Ayrshire in Southwest Scotland apparently is endowed with a geology that lends itself towards the formation of rocking stones. Several rocking stones, or stones that used to rock at one time, are there.

A rocking stone that some associate with the Druids is on Cuff Hill in Hessilhead, near Beith in North Ayrshire. It no longer rocks due to people digging beneath to ascertain its fulcrum.[15] It is in a small wood and surrounded by a circular drystone wall. An article was published in the Cumnock Chronicle in 1907 on the reason for the stone being dislodged.

The Ogrestone or Thurgartstone near Dunlop in East Ayrshire is thought to have been a rocking stone. However, soil has built up around the base of the Thurgatstone over the years, which now prevents any rocking motion.

A rocking stone existed in 1913–1919 at Sannox on Arran, on a nearly horizontal platform next to the seashore.[16]

The Lamagee or Lamargle stone in Lugar as previously mentioned is in the center of a loose collection of stones in the village of Lugar in East Ayrshire. The Lamargle stone rests on two stones. Local legend has it that the Lamargle stone used to rock, but it no longer does. The Witch's Stone or Boarstone on the Craigs o'Kyle is recorded by the author John Smith as having rocked.[citation needed]

The Clochoderick Rocking Stone

The Clochoderick Stone near Howwood and Kilbarchan in Renfrewshire used to rock, and it is said that the Druids used it to judge people. The accused was made to sit on the stone and by the way it moved, the Druids judged the innocence or guilt of the individual. It is also said to be the burial place of Rhydderch Hael, King of Strathclyde, who was the victor at the Battle of Arderydd near Arthuret in the Borders. His victory brought Christianity to Strathclyde. This stone is very unusual and is a SSSI for Geology in its own right.[citation needed]

Dislodged rocking stones

[edit]

Often wear, erosion, or human intervention has resulted in the dislodging of rocking stones.

Devon

[edit]

A well-known rocking stone or logan stone was located at Sharpitor near Lustleigh on Dartmoor. It was also called the Nutcrackers Stone, sometimes seen on Ordnance Survey maps. The huge stone once lay overhanging Lustleigh Cleave until 1951, when it was deliberately pushed down the valley. A failed attempt to rescue the stone by pulling it back up the valley resulted in it breaking into pieces.[17]

Around 1900 there were rocking stones at Rippon tor, and Sittaford tor on Dartmoor.[18]

Larchmont, New York

[edit]

A 150-ton glacial erratic occurs on Rockingstone Avenue in Larchmont, New York, that was so perfectly balanced that just a small touch would allow it to rock back and forth. In the 1920s, blasting for a new sewer system in the neighbourhood dislodged the rock, and it longer balances.

Pembrokeshire

[edit]

A rocking stone in Pembrokeshire is described in Gibson's edition of Camden's Britannia, from a manuscript account by George Owen:

"This shaking stone may be seen on a sea-cliff within half a mile of St. David's. It is so vast that I presume it may exceed the draught of an hundred oxen, and it is altogether rude and unpolished. The occasion of the name (Y maen sigl, or the Rocking-stone) is for that being mounted upon divers other stones about a yard in height it is so equally poised that a man may shake it with one finger so that five or six men sitting on it shall perceive themselves moved thereby."

Cromwell's soldiers rendered the rocking stone of Pembrokeshire immovable after Mr. Owen had described it. They reportedly destroyed it because they felt it encouraged superstition.

Golcar Hill

[edit]

Another rocking stone was at Golcar Hill, near Halifax in Yorkshire. However, the Golcar Hill rocking stone will no longer easily rock because some masons wanted to find out how such a large weight could move so easily, so they chopped at it until they destroyed its balance.

Men Amber

[edit]

A very sensitive rocking stone called Men Amber (sometimes written as Men-Amber or Menamber, from the Cornish men omborth meaning balance stone) was on a high ridge in the parish of Sithney, near Helston, Cornwall. It is 11 feet (3.4 m) long, 4 feet (1.2 m) deep, and 6 feet (1.8 m) wide. It was toppled by Shrubsall, the governor of Pendennis, and his men about 1650 during Cromwell's Commonwealth. One rumoured motivation for the dislodging was a purported prophecy of Merlin, who supposedly said that Men Amber would stand until England had no king.

Rev. Dr. William Stukeley wrote:

Main Ambres; petrae ambrosiae, signify the stones anointed with holy oil, consecrated; or in a general sense, a temple, altar or places or worship

William Borlase in his 1754 book Antiquities of Cornwall, claimed that Men Amber was dislodged because:

the vulgar used to resort to this place at particular times of the year, and paid to this rock more respect than was thought becoming to good Christians.

Logan Rock

[edit]
The Logan Rock at Trereen Dinas

Another well-known example of a rocking or logan stone is Logan Rock of Treen in Cornwall. This huge stone weighs about 80 or 90 tons. It is one of the best-known rocking stones for several reasons. For example, Modred, in William Mason's dramatic poem "Caractacus" addressing the characters Vellinus and Elidurus, says of the Logan Rock:

Thither, youths,
Turn your astonish'd eyes; behold yon huge
And unhewn sphere of living adamant,
Which, poised by magic, rests its central weight
On yonder pointed rock: firm as it seems,
Such is the strange and virtuous property,
It moves obsequious to the gentlest touch
Of him whose breast is pure; but to a traitor,
Tho' ev’n a giant’s prowess nerv’d his arm,
It stands as fixt as Snowdon.

However, another reason that the Logan Rock of Treen is remembered is that it was the center of a famous drama. In April 1824, Lieutenant Hugh Goldsmith, R. N. (nephew of the famous poet Oliver Goldsmith), and 10 or 12 of his crew of the cutter HMS Nimble, armed with bars and levers, rocked the huge granite boulder until it fell from its cliff-top perch. Goldsmith was apparently motivated to disprove the claim of Dr. Borlase, who wrote in Antiquities of Cornwall in 1754 that:

In the parish of S. Levan, there is a promontory called Castle Treryn. This cape consists of three distinct groups of rocks. On the western side of the middle group near the top, lies a very large stone, so evenly, poised that any hand may move it to and fro; but the extremities of its base are at such a distance from each other, and so well secured by their nearness to the stone which it stretches itself upon, that it is morally impossible that any lever, or indeed force, however applied in a mechanical way, can remove it from its present situation.

The Logan Rock (circled) seen from Pednvounder beach

Goldsmith was determined to demonstrate that nothing was impossible when the courage and skill of British seamen were engaged. The Logan Rock fell and was caught in a narrow chasm.

This upset the local residents considerably, since Logan Rock had been used to draw tourists to the area. Sir Richard Vyvyan (1800–1879)[19] was particularly unhappy. They demanded that the British Admiralty strip Lieutenant Goldsmith of his Royal Navy commission unless he restored the boulder to its previous position at his own expense. However, Mr. Davies Gilbert persuaded the Lords of the Admiralty to lend Lieutenant Goldsmith the required apparatus for replacing the Logan Rock. The Admiralty sent 13 capstans with blocks and chains from the dock yard at Plymouth, and contributed £25 towards expenses. Gilbert also raised more funds.[20]

The Logan Rock (top right) in context

After months of effort, at 4:20 pm on 2 November 1824, in front of thousands of spectators and with the help of more than 60 men and block and tackle, the Logan Rock was finally repositioned and returned to "rocking condition".[21] Apparently, the total final cost of this enterprise was £130 8s 6d. However, it is not clear how much of the remaining £105 Goldsmith had to make up out of his own pocket.

For some time after, the rock was kept chained and padlocked, but eventually these restrictions were removed, and the rock was set free. However, it apparently no longer vibrates or "logs" as easily as it did before.

Tourism dropped, and this was blamed on the condition of Logan Rock. For a while, Treen was nicknamed 'Goldsmith's Deserted Village'.

Another famous rock structure, Lanyon Cromlech, was knocked down during a thunderstorm in 1815. The same machinery that was used to restore the Logan Rock in Treen was successful in repositioning Lanyon Cromlech.

Beliefs

[edit]
Rocking Stone 'Maen Sigl' Great Orme Llandudno

A wide variety of beliefs are associated with rocking stones. Because of their strange nature, rocking stones were sometimes associated with witchcraft, or Druids.

The rocking stone near Nancledrea in Cornwall was said to only move at midnight when witches were out. People claimed that if one touched the rocking stone nine times at midnight, one would turn into a witch.

The Brimham rocking stone in Yorkshire is said to rock only for the efforts of an honest man.[22]

The rocking stone at Land's End was said to have been placed there by a giant who used it to rock himself to sleep.

It was claimed that the Logan Stone in Treen could cure childhood diseases. The children were rocked on the Logan Stone in certain seasons. People say that the charm was broken when Lieutenant Goldsmith dislodged the Logan Stone.

It is a Cornish tradition to make a vow and then attempt to move a rocking stone, or logan rock. It was said that no persons with treachery in their hearts could make a rocking stone move.

See also

[edit]

References

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia
from Grokipedia
A rocking stone, also known as a logan stone or logging stone, is a naturally occurring geological formation consisting of a large boulder delicately balanced atop a smaller pedestal or contact point, enabling it to oscillate or rock gently under minimal force—such as a human touch—while returning to its equilibrium position due to a low center of gravity. These formations are typically composed of hard, durable rock like granite that has been shaped over millennia. Rocking stones form primarily through processes of and differential , where softer underlying rock layers are gradually worn away by wind, rain, frost, and other agents, leaving a rounded supported by a narrow, harder neck or base. Many examples are glacial erratics, boulders transported long distances by ancient glaciers and deposited in precarious positions during the last , with subsequent refining their balance. This combination of glacial action and long-term weathering creates the instability that defines them, though human interference or natural shifts can sometimes render them immobile. One of the most famous rocking stones is the (Cornish: Men Omborth, meaning "balanced stone") near in , , a massive 80-tonne boulder perched 30 meters above the sea on the cliffs of Treryn Dinas. In 1824, British Navy Hugh Goldsmith and his crew dislodged it using handspikes as a prank, prompting local outrage and a restoration effort funded primarily by Goldsmith himself, with assistance from the Admiralty and local benefactor Davies Gilbert, which re-erected it using cranes and winches at a cost equivalent to about £18,000 today. The incident, which temporarily halted to the site, highlighted the cultural and economic value of these natural wonders, often linked to ancient legends of Druidic rituals or powers. Other notable examples include the Rocking Stone at Kidston Lake Park in Halifax, Nova Scotia, a glacial erratic estimated at 147–431 tonnes, documented since 1823 and now protected as a municipal heritage site. In the United States, formations like the Balanced Rock in Arches National Park, Utah—composed of Entrada Sandstone atop softer layers—exemplify similar erosional processes, though not all retain the rocking motion due to stability or damage. These sites attract geologists, tourists, and historians, underscoring rocking stones' role in illustrating Earth's dynamic geological history.

Definition and Terminology

Definition

A rocking stone is a large, naturally occurring that is precariously balanced on a small pivot or fulcrum, enabling it to rock or tilt with minimal applied force while remaining enough not to topple or dislodge from its position. These formations typically weigh several tons and rest on a tiny contact area that acts as a fulcrum, often allowing a single person or a small group to set the stone in motion through gentle pushing or pulling. The balance arises from the stone's being positioned such that it occupies a local equilibrium within a broader unstable configuration, permitting oscillatory movement without permanent displacement. Rocking stones differ from standing stones or menhirs, which are upright monoliths typically erected by human intervention and lack the dynamic rocking capability due to their broad base and fixed orientation. In contrast to static balanced rocks, which maintain equilibrium without rocking under normal conditions, rocking stones exhibit inherent that facilitates motion with slight perturbation.

Alternative Names

Rocking stones are known by several alternative names that reflect their precarious balance and rocking motion, with "logan stone" being one of the most prominent synonyms derived from the English "log," meaning to rock or sway. This term, also appearing as "logging stone," emerged in the and is particularly associated with British examples, where it describes boulders that can be gently oscillated with minimal force. In regional variations, particularly in Cornwall—a region with Celtic linguistic influences—the term "Men Omborth" (historically recorded as "Men Amber") has been used for specific logan stones, where "men" in Cornish denotes a stone and "omborth" means balanced or poised, as seen in historical accounts of sites like the one near Nancegollan. Welsh nomenclature includes "cryd," meaning cradle, as in "Cryd Tudno" on the , evoking the stone's gentle swaying like a cradled . In , these formations are often called "balanced rocks," emphasizing their equilibrium rather than motion, though the term overlaps with rocking stones in descriptions of glacial erratics. The phrase "rocking stone" itself originated in 18th-century , appearing in and travel accounts to describe such geological curiosities across the Isles. The use of "logan" gained wider popularity in the through documented Cornish examples, such as the near , which drew scientific and following its displacement in 1824. Additionally, modern geological terminology includes "precariously balanced rock" or PBR, a term used in studies of seismic hazards to denote boulders at risk of toppling, highlighting their instability without direct reference to rocking.

Geological Origins

Formation Processes

Rocking stones primarily form through , a process that combines chemical and physical mechanisms to round jointed into near-spherical corestones while decomposing the surrounding material into softer . This weathering initiates along preexisting joints and fractures in the rock mass, where water infiltration promotes mineral alteration and expansion, preferentially eroding corners and edges to produce concentric layers of rindlets around a resistant core. Subsequent exposure of these corestones occurs via differential , which removes the overlying or surrounding weathered material, leaving the rounded boulders perched on pedestals of unweathered or less-eroded rock. Mechanisms include glacial scouring that strips away in formerly glaciated regions, river undercutting that lowers the base level around outcrops, and general surface driven by wind, water, or in upland areas. This exhumation stage often follows tectonic uplift or climatic shifts that enhance erosional rates, resulting in the delicate balance characteristic of rocking stones. The process typically affects hard, jointed rocks, including igneous (such as ), metamorphic (such as ), and sedimentary (such as ), which resist complete breakdown and develop uniform spheroidal shapes due to their mineral composition and patterns. Volcanic tuffs and basaltic rocks can also form similar features under appropriate conditions. Formation unfolds over geological timescales, from thousands to millions of years, with weathering rates varying by rock type and environment— for instance, conversion to proceeds at 43–58 meters per million years in humid tropical settings. plays a crucial role, particularly in temperate zones where freeze-thaw cycles expand in fractures to accelerate mechanical disintegration, while consistent supports chemical reactions like in humid regions.

Physical Principles

Rocking stones maintain their precarious balance due to a low center of gravity positioned close to a small fulcrum or pivot point at the base, which permits gentle oscillation under minimal applied torque while resisting full overturning. The torque required to initiate tipping is given by τ=F×r\tau = F \times r, where FF is the horizontal force and rr is the lever arm distance from the fulcrum to the line of action of the force; this allows small perturbations, such as wind or human pushing, to cause rocking, but significantly greater energy is needed to rotate the stone beyond its tipping angle and achieve permanent displacement. Key stability factors include the coefficient of friction μ\mu at the contact surface, which must satisfy μtanβ\mu \geq \tan \beta (where β\beta is the tilt ) to prevent sliding before tipping occurs, and the dynamics of rocking motion, where gravitational restoring combines with the rock's to return it to equilibrium after small displacements. The period of small-angle oscillations for a rocking stone can be approximated using the physical pendulum model: T=2πImgd,T = 2\pi \sqrt{\frac{I}{m g d}},
Add your contribution
Related Hubs
User Avatar
No comments yet.